1. Field of the Invention
The present invention relates in general to the field of information handling system power supply, and more particularly to a system and method for managing power provided to a portable information handling system.
2. Description of the Related Art
As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option available to users is information handling systems. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems.
Portable information handling systems have, in particular, grown considerably popular with end users in recent years. Portable information handling systems have internal batteries to power the system without a need for an external power source, such as an AC outlet. An internal battery provides end users with greater flexibility by allowing free movement with the system while the system is running. One concern in the design and use of portable information handling systems is the availability of sufficient battery life in the system to provide a reasonable operating time before the battery charge expires and a recharge is needed. In order to enhance battery life, portable information handling systems are typically built with power efficient components and typically include power management systems that throttle or idle processing components when on battery power. Generally, power management systems do not have to reduce component power consumption when the portable information handling system is plugged into an external power source. Power provided from the external power source is directed primarily to run the components operating on the information handling system with any extra power diverted to charge the battery.
As processing components have become more powerful over time, the power consumed by them has tended to increase. One difficulty that has arisen due to this increased power consumption is that peak power consumption levels for an information handling system can exceed the power rating of the adapter that provides external power to the system. Adapters typically have a crow-bar safety system that will trip if power drawn from the adapter exceeds the adapter power rating. Generally, adapters are built with an operating margin that allows them to run at slightly greater than the power rating for extended periods of time without tripping the crow-bar circuitry. This, however, presents a difficulty since UL specifications require that an information handling system average input current not exceed the adapter's current rating. With higher performing processor and graphics solutions as well as an increasing number of features, a maximally-configured system operating at peak power consumption can draw power at a rate that exceeds the UL specification for the adapter with or without tripping the crow-bar circuitry. Systems are not allowed to ship if a violation of the UL specification occurs. The risk of such a violation is enhanced when tolerances relating to power management and measurements stackup to reduce the effective output of the power adapter.